Ostrogski Castle, or, strictly speaking, Gniński Palace (Ordynacki Palace)
Prince Janusz Ostrogski began to erect a castle. In 1681, it was acquired by the Under-Chancellor to the Crown, Jan Gniński. The design of a huge palatial complex was entrusted to Tylman van Gameren. The heir to the castellan, Voivod Jan Gniński, completed the building of the residence.
As it stands today, the palace is the left annexe of a huge, unfinished concept. It was redeveloped in the 18th and 19th centuries. Following its destruction during the ravages of war, it was reconstructed, between 1949 and 1953, by Mieczysław Kuzma. He returned to Tylman van Gameren's design, though he did modify the appearance of the interior.
The Palace had several owners and fulfilled a variety of functions. In 1859, it became home to the Institute of Music; during the interwar years, it housed a conservatoire and theatre school; and, after the war, the palace was granted to the Fryderyk Chopin Institute. Not long after, it became the headquarters of the Fryderyk Chopin Society and the Fryderyk Chopin Museum.